It is the southernmost island of the Cyclades group of Greece, in the Aegean Sea. It is the remaining eastern half of an exploded volcano. In ancient times, it was known as Calliste ("Most Beautiful") and had been inhabited since before 2000 BC. In ~1628 BC, one of the largest volcanic eruptions occurred. The force of this explosion was equivalent to the detonation of about 150 Hydrogen Bombs. An 800-foot tidal wave went 30-miles inland, on the surrounding mainlands. This eruption was recorded all over the world. In Egypt, the royal scribes recorded nine days of darkness caused by a dense cloud of ash. The scribes in China also recorded the cloud of ash. It was also recorded in nature. In the bristle cone trees in California, US, the tree-ring formations are dramatically smaller in the 1620s BC suggesting a period of darkness. In the 1980s AD, scientists took core samples from the icecap on Greenland and found a layer of ash in the layers following 1628 BC. In 1967, the Greek archaeologist Spyridon Marinatos found the remains of a city preserved by the volcanic ash on Thera. It is a Minoan city that has large, well-built, multi-story houses, which hold a number of the best Minoan frescoes discovered in the Mediterranean. The frescoes are found in every room and depict the people of Thera, swallows, antelopes, and monkeys to name a few. The city also has fountains, plumbing (with hot and cold water), flush toilets and bathtubs. The explosion of Thera inspired the story of Atlantis and parts of the Old Testament book of Exodus.